I installed the codec pac in my administrator user and all is working well in that account. All the thumbnails appear properly. However, in my normal user account,my RAW files and my PSD files are still shown with their default icons. Can you tell me how I can correct this?

Yes this has been observed on some systems. The reason is that the installer is prevented to write the registration key to the normal per-machine location during setup. Instead of failing, the installer falls back to a per-user location, so the codecs at least work for the installing user.

The reason may be the actions of an overzealous anti-virus, or non-default registry permissions preventing write access to the needed location.

The workaround is as follow:

Un-install the product, then re-install if from the user account where it did not work.

Yes build 308 has an inadvertent bug which disabled WCS (for those users who had explicitly enabled it in the program options). If you uncheck the "Use Windows Color System" option on the "Personalization" page, the standard color engine gets used and color-management works again. The problem has been corrected and the download servers was updated.

Not sure about your other remark. People mess with their system with free utilities supposed to "clean", "speedup" or "protect" their computers and do all kinds of other supposedly good things.

Most of the time however, those programs cause more harm than good, and users - who likely ignored warnings and clicked OK to everything in those utilities - end up with computer no longer working as intended, THEN turn to software vendors like us to report various malfunctions, caused by their own actions (sometimes unknowingly).

Reinstalling Windows on a blank disk and refraining for ever messing again with security settings and registry permissions cures many of the alleged problems, including the one described in this thread.